MITOCHONDRIAL DNA ANALYSIS OF TILAPIA FROM SELECTED WATER BODIES IN GHANA

Fishery stocks the world over are gradually being depleted due to overexploitation therefore it has become imperative to supplement wild stocks with farmed or cultured fish. Ghana has a huge potential to grow its aquaculture sector to ensure that the protein deficit is mitigated. Research conducted on tilapia in Ghana is mostly done on the Volta Lake which is the largest by surface area and third largest by volume man-made lake in the world to the neglect of smaller but equally important water bodies. Therefore this study was conducted to determine the various populations of tilapia that exists in selected water bodies in Ghana, identify the various species via Mitochondrial DNA (mtDNA) and to find alternative tilapia stock sources apart from the Volta Lake

Samples were collected from six different water bodies (Avu lagoon, Weija lake, Fosu Lagoon, Barekese dam, Densu estuary, Kpeshie lagoon) in Ghana and preserved in 96-99% alcohol. Genomic DNA was extracted from fin clips using the phenol-chloroform method. Polymerase chain reaction (PCR) for the mtDNA control region (D-loop) was done using the universal vertebrate primer T-L19 and T-H98 and samples were sequenced.

Avu lagoon recorded the highest number of species with five species (O. niloticus, T. rendalli, T. zillii, S. galilaeus and H. elongatus*) followed by Barekese dam with two species (O. niloticus and S. galilaeus). Weija recorded one species (O. niloticus) whilst Densu, Kpeshie and Fosu recorded one species (S. melanotheron) at each location.

*This was identified by observation as T. mariae but mtDNA showed it to be H. elongatus.